Adding friction material to timing belts

[GeeTwo]

I'm guessing that you're using this for a lift/feeder or similar traction mechanism.

Something to consider in addition to the connection: the grip material must either be in discrete pieces, or must stretch enough to allow the belt to pass around the smallest pulley you're going to use despite the lamination. I've never done this, but it seems that a relatively thin layer of rubber cement or silicone adhesive applied to the outside of the belt would serve both as the adhesive and (once it cured) the grip surface, and would have the necessary give. Durability of these may be an issue. I'd recommend getting several short belts and trying a number of different adhesives in a small test rig to see if you can find any that hold, wear well, and don't chemically damage the timing belt.